The present invention relates to a rotary type cylinder device capable of dealing with interconversion of reciprocating motions of pistons in cylinders and a rotary motion of a shaft, more precisely relates to a rotary type cylinder device which can be applied to internal-combustion engines, compressors, vacuum pumps, hydraulic rotary machines, etc.
In each of internal-combustion engines, compressors, vacuum pumps, hydraulic rotary machines, etc., various types of driving mechanisms are employed. For example, a reciprocal type driving mechanism in which a fluid is repeatedly sucked and discharged by reciprocating motions of piston units connected to a crank shaft, a scroll type driving mechanism in which a fluid is repeatedly sucked and discharged by revolving a movable scroll with respect to a fixed scroll, a rotary type driving mechanism in which a fluid is repeatedly sucked and discharged by rotary motion of a roller (see Japanese Laid-open Patent Publication No. P2004-190613A), a screw type driving mechanism, and a vane type driving mechanism are employed according to usage.
Especially, the reciprocal type driving mechanism is mainly used for internal-combustion engines, compressors, vacuum pumps, etc., each of which is rotated at a medium speed, e.g., 10000 rpm, and in each of which high airtightness is required.
In the reciprocal type driving mechanism, energy converting efficiency is easily lowered by energy loss caused by reciprocating motion of piston units in cylinders. Further, a connection rod for supporting the piston units reciprocally moved in the cylinders, a crank shaft being connected to the connecting rod and a crank arm being connected to the crank shaft are required, so an energy converting device, which converts the reciprocating motion of the piston units into a rotary motion, must be large in size. Vibration, which is caused by deviations of mass balances (gravity centers) of rotatable members while the piston units are reciprocally moved, must be absorbed by a damper, etc.